Sensor

ABSTRACT

A sensor includes a base plate and a generally vertically extending tubular guide provided intermediate the ends thereof with two diametrically opposed radial openings. A firing pin is slidably mounted within the guide and is spring biased toward one end of the guide to an actuated position wherein the pin engages a cartridge to fire the cartridge and actuate an inflatable cushion of an occupant restraint system. An annular seismic mass surrounds the guide and is pivotally supported thereon for movement about an axis transverse of the guide axis and direction of movement of the operator. The mass axis is further coplanar with the axis of the openings in the guide. The mass includes a pair of diametrically opposite axially and radially directed shoulders having grooves which open to the guide openings and cooperate with an annular groove on the firing pin to trap respective balls therebetween and detent the firing pin against movement. The balls are freely received within the guide openings. When the mass receives an acceleration pulse of predetermined amplitude and time directed angularly and preferably normal to the axis thereof, it swings about the axis to move the grooves thereof out of engagement with the balls and permit the firing pin spring to move the firing pin to actuated position as the balls move outwardly of the guide openings.

ilit te Cwycyshyn et al.

[ 1 SENSOR [75] Inventors: Walter Cwycyshyn, Detroit; Elwyn L. Kitchen,Jr., Troy, both of Mich.

[73] Assignee: General Motors Corporation, De-

troit,l\ iich.

22 Filed: Apr. 23,1971

21 Appl.No.:13 6,88O

[52] US. Cl 73/514, 102/78, 116/114 AH [51] llnt. Cl. ..G0lp 15/02 [58]Field of Search ..102/73, 78, 72, 7; 73/514, 492; 116/114 AH PrimaryExaminer-Samuel W. Engle Att0rney-W. E. Finken and Herbert Furman [57]ABSTRACT A sensor includes a base plate and a generally verticallyextending tubular guide provided intermediate the ends thereof with twodiametrically opposed radial openings. A firing pin is slidably mountedwithin the guide and is spring biased toward one end of the guide to anactuated position wherein the pin engages a cartridge to fire thecartridge and actuate an inflatable cushion of an occupant restraintsystem. An annular seismic mass surrounds the guide and is pivotallysupported thereon for movement about an axis transverse of the guideaxis and direction of movement of the operator. The mass axis is furthercoplanar with the axis of the openings in the guide. The mass includes apair of diametrically opposite axially and radially directed shouldershaving grooves which open to the guide openings and cooperate with anannular groove on the firing pin to trap respective balls therebetweenand detent the firing pin against movement. The balls are freelyreceived within the guide openings. When the mass receives anacceleration pulse of predetermined amplitude and time directedangularly and preferably normal to the axis thereof, it swings about theaxis to move the grooves thereof out of engagement with the balls andpermit the firing pin spring to move the tiring pin to actuated positionas the balls move outwardly of the guide openings.

5 Claims, 4 Drawing Figures Patented May 1, 1973 IN VENTORS I! m IATTORNEY SENSOR This invention relates generally to sensors and moreparticularly to sensors of the type including a seismic mass movableunder an acceleration pulse of predetermined amplitude and time torelease a detented operator for movement to actuated position.

One of the features of the sensor of this invention is that the seismicmass is pivoted for movement under the acceleration pulse about an axistransverse to the direction of movement of the operator, with theswinging movement of the mass undenthe pulse releasing the operatordetent. Another feature of this invention is that the operator movesaxially of an elongated guide and that the mass includes a plurality ofaxially and radially directed shoulders cooperating with shoulders ofthe operator to detent balls therebetween and detent the operatoragainst biased movement to actuated position. A further feature of thisinvention is that the shoulders of the mass include grooves directedaxially and radially of the guide and coplanar with the mass axis forengaging the balls. Yet another feature of this invention is that theoperator includes an annular groove which cooperates with respectivegrooves of the mass shoulders to detent the balls therebetween andthereby hold the operator against biased movement.

These and other features of the sensor of this invention will be readilyapparent from the following specification and drawings wherein:

FIG. 1 is a sectional view ofa sensor according to this invention inunactuated position;

FIG. 2 is a sectional view taken generally along the plane indicated byline 2-2 of FIG. 1;

FIGS is a view taken generally along the plane indicated by line 3-3 ofFIG. 1; and

FIG. 4 is a view similar to FIG. 1 showing the sensor in actuatedposition.

Referring now to FIGS. 1 through 3 of the drawings, a sensor accordingto this invention includes a generally rectangularly shaped base ormounting plate 12 having a central cylindrical depression 14 and a pairof laterally extending apertured ears 16, FIG. 3, which provide forsecurement of the plate 12 to a suitable support, such as a portion ofavehicle body.

A cylindrical guide tube 18 includes a partially flanged one end 20which seats within the depression 14. The other end of the tube 14 isreceived within a counterbore of a cylindrical member 22 and engages theflange of a conventional cartridge 24 to locate and retain the cartridge24 within the member 22. A cover 26 of generally rectangular crosssection includes an upper wall 28 having a cylindrical extension 30which partially surrounds the member 22 and has its terminal or freeedge 32 crimped within an annular groove of the member 22 to therebysecure this member to the cover. The cover seats on plate 12 andincludes a return bent flange 34 which extends over the sides of theplate 12 except in the area of the cars 16. At a number of places 36,the flange 34 is crimped over the plate 12 to assemble the cover to thisplate. A sealing bead or washer 38 is provided between the flange 34 andthe plate 12 to seal the sensor.

A generally cylindrically shaped seismic mass 40 includes a generallyoval shaped central bore 42, FIG. 3, receiving the guide tube 18therethrough. The tube 18 includes an intermediate annular integral rib44 which locates an annular mounting member 46 secured to the outersurface of the tube. As shown in FIG. 2, member 46 includes a pair ofdiametrically aligned openings which receive respective guide shafts orpins 48 which in turn are secured within respective diametricallyaligned openings in the mass 40. Thus the mass 40 is mounted on the tube14 for pivotal movement about an axis transverse of the axis of thetube.

A cylindrical firing pin 50 is slidably received within the tube 18 anda coil compression spring 52 seating between the lower end of the firingpin and the flanged end 20 of tube 18 continually biases the firing pinupwardly of the tube or from its unactuated position shown in FIGS. 1and 2 to its actuated position shown in FIG. 4 wherein the tapered point54 of the firing pin engages the cartridge 24 to fire the cartridge.Although not shown in the drawings, it will be understood that thecartridge 24 may be connected by suitable means, such as pyrocord, withdetonators or other suitable means providing rupture of a diaphragm of apressure vessel in order to permit the release of the contents of thevessel for inflation of an inflatable occupant restraint cushion.Alternatively, the firing pin 50 may be elongated and the tapered point54 thereof may be located outwardly of the member 22 when in actuatedposition so as to directly rupture such a diaphragm or to directly fireor initiate the firing of detonators controlling rupture of such adiaphragm. Alternatively, the firing pin may close a switch initiatingelectrical rupture of the diaphragm or electrical ignition of a gasgenerator.

The firing pin 52 includes a shoulder means or peripheralsemi-cylindrical continuous groove 56 and the guide tube 18 includes apair of diametrically opposite enlarged cylindrical openings 58, asshown in FIG. 2. The mass 40 includes a pair of diametrically oppositeextensions or shoulders 60 along its minor axis, each of which includesan axially and radially tapered planar surface 62 provided with ashoulder means or shallow groove 64. The centers of generation of thegrooves 64 are coplanar with the mass axis of movement defined by pins48. As shown in FIGS. 2 and 3, a ball 66 is received within each of theopenings 58 in engagement with the groove 56 and a respective groove 64under the biasing action of the spring 52 to normally detent orreleasably hold the firing pin 50 in its unactuated position and holdthe mass 40 against movement.

When an acceleration pulse of predetermined amplitude and time isreceived by the mass 40 and is directed generally normal to the planecontaining the axis thereof and the centers of generation of grooves 64,the mass 40 will .swing about the axis thereof to move the grooves 64out of engagement with the balls 66 and permit release of the firing pin50 under the action of spring 52 for movement to actuated position. Themovement of the mass about its axis is accompanied by a slight radialinward and downward movement of the balls 66 and a slight furthercompression of spring 52 prior to release of the balls 66.

It will further be noted that the axis defined by the pins 48 isgenerally parallel to and coplanar with the axes of the openings 58 andthe centers of the balls 66.

Thus, this invention provides an improved sensor.

We claim:

l. A sensor comprising, in combination, a support, an elongated annularguide secured to the support, an operator mounted within the guide formovement between actuated and unactuated positions, means biasing theoperator to actuated position, a seismic mass, shaft means pivotallymounting the mass on the guide for movement independently thereof abouta fixed axis transverse of the direction of movement of the operator,cooperating pairs of shoulder means on the operator and mass, a ballengageable with each cooperating pair of shoulder means to block pivotalmovement of the mass and hold the operator in unactuated position, saidseismic mass being responsive to an acceleration pulse of predeterminedamplitude and time directed generally angularly to the mass axis toswing the mass about such axis and move the shoulder means thereof outof cooperating relationship to the operator shoulder means to permit thebiasing means to move the operator to actuated position as the ballsmove out of engagement with each pair of shoulder means.

2. A sensor comprising, in combination, a support, an elongated annularguide secured to the support, an operator mounted within the guide formovement between actuated and unactuated positions, means biasing theoperator to actuated position, a seismic mass, shaft means pivotallymounting the mass on the guide for movement independently thereof abouta fixed axis transverse of the direction of movement of the operator,shoulder means on the operator, a plurality of shoulder means on themass, each directed axially and radially of the direction of movement ofthe operator and respectively associated in pairs with the operatorshoulder means, a ball engageable with each cooperating pair of shouldermeans to block pivotal movement of the mass and hold the operator inunactuated position, said seismic mass being responsive to anacceleration pulse of predetermined amplitude and time directedgenerally angularly to the mass axis to swing the mass about such axisand move the shoulder means thereof out of cooperating relationship tothe operator shoulder means to permit the biasing means to move theoperator to actuated position as the balls move out of engagement witheach pair of shoulder means.

3. A sensor comprising, in combination, a support, an elongated annularguide secured to the support, an operator mounted within the guide formovement between actuated and unactuated positions, means biasing theoperator to actuated position, a seismic mass, shaft means pivotallymounting the mass on the guide for movement independently thereof abouta fixed axis transverse of the direction of movement of the operator,cooperating pairs of arcuate shoulder means on the operator and mass, aball tangentially engageable with each cooperating pair of shouldermeans to block pivotal movement of the mass and hold the operator inunactuated position, the centers of generation of the arcuate shouldermeans being coplanar with the mass axis and centers of the balls, saidseismic mass being responsive to an acceleration pulse of predeterminedamplitude and time directed generally normal to such plane to swing themass about the axis thereof and move the shoulder means thereof out ofcooperating relationship to the operator shoulder means to permit thebiasing means to move the operator to actuated position as the ballsmove out of engagement with each pair of shoulder means.

4. A sensor comprising, in combination, a support, an elongated annularguide secured to the support, an annular operator mounted within theguide for movement between actuated and unactuated positions andincluding a peripheral radially outwardly opening groove, means biasingthe operator to actuated position, a seismic mass, shaft means pivotallymounting the mass on the guide for movement independently thereof abouta fixed axis transverse of the direction of movement of the operator, apair of grooves on the mass opening toward the operator groove anddirected axially and radially of the mass axis, each cooperating withthe operator groove to provide cooperating pairs of shoulder means, aball engageable with each cooperating pair of shoulder means to blockpivotal movement of the mass and hold the operator in unactuatedposition, said seismic mass being responsive to an acceleration pulse ofpredetermined amplitude and time directed generally angularly to themass axis to swing the mass about such axis and move the grooves thereofout of cooperating relationship to the operator groove to permit thebiasing means to move the operator to actuated position as the ballsmove out of engagement with each pair of shoulder means, a planebisecting the grooves containing the mass axis and the centers of theballs.

5. A sensor comprising, in combination, a support, an elongated annularguide secured to the support, an operator mounted within the guide formovement between actuated and unactuated positions, means biasing theoperator to actuated position, an annular seismic mass surrounding theguide, shaft means pivotally mounting the mass adjacent one end thereofon the guide for independent movement relative thereto about a fixedaxis transverse of the direction of movement of the operator,cooperating pairs of shoulder means on the operator and mass adjacentthe other end thereof, a ball engageable with each cooperating pair ofshoulder means to block pivotal movement of the mass and hold theoperator in unactuated position, the centers of the balls being coplanarwith the mass axis, said seismic mass being responsive to anacceleration pulse of predetermined amplitude and time directedgenerally normal to the mass axis and intermediate the ends thereof toswing the mass about such axis and move the shoulder means thereof outof cooperating relationship to the operator shoulder means to permit thebiasing means to move the operator to actuated position as the ballsmove out of engagement with each pair of shoulder means.

1. A sensor comprising, in combination, a support, an elongated annularguide secured to the support, an operator mounted within the guide formovement between actuated and unactuated positions, means biasing theoperator to actuated position, a seismic mass, shaft means pivotallymounting the mass on the guide for movement independently thereof abouta fixed axis transverse of the direction of movement of the operator,cooperating pairs of shoulder means on the operator and mass, a ballengageable with each cooperating pair of shoulder means to block pivotalmovement of the mass and hold the operator in unactuated position, saidseismic mass being responsive to an acceleration pulse of predeterminedamplitude and time directed generally angularly to the mass axis toswing the mass about such axis and move the shoulder means thereof outof cooperating relationship to the operator shoulder means to permit thebiasing means to move the operator to actuated position as the ballsmove out of engagement with each pair of shoulder means.
 2. A sensorcomprising, in combination, a support, an elongated annular guidesecured to the support, an operator mounted within the guide formovement between actuated and unactuated positions, means biasing theoperator to actuated position, a seismic mass, shaft means pivotallymounting the mass on the guide for movement independently thereof abouta fixed axis transverse of the direction of movement of the operator,shoulder means on the operator, a plurality of shoulder means on themass, each directed axially and radially of the direction of movement ofthe operator and respectively associated in pairs with the operatorshoulder means, a ball engageable with each cooperating pair of shouldermeans to block pivotal movement of the mass and hold the operator inunactuated position, said seismic mass being responsive to anacceleration pulse of predetermined amplitude and time directedgenerally angularly to the mass axis to swing the mass about such axisand move the shoulder means thereof out of cooperating relationship tothe operator shoulder means to permit the biasing means to move theoperator to actuated position as the balls move out of engagement witheach pair of shoulder means.
 3. A sensor comprising, in combination, asupport, an elongated annular guide secured to the support, an operatormounted within the guide for movement between actuated and unactuatedpositions, means biasing the operator to actuated position, a seismicmass, shaft means pivotally mounting the mass on the guide for movementindependently thereof about a fixed axis transverse of the direction ofmovement of the operator, cooperating pairs of arcuate shoulder means onthe operator and mass, a ball tangentially engageable with eachcooperating pair of shoulder means to block pivotal movement of the massand hold the operator in unactuated position, the centers of generationof the arcuate shoulder means being coplanar with the mass axis andcenters of the balls, said seismic mass being responsive to anacceleration pulse of predetermined amplitude and time directedgenerally normal to such plane to swing the mass about the axis thereofand move the shoulder means thereof out of cooperating relationship tothe operator shoulder means to permit the biasing means to move theoperator to actuated position as the balls move out of engagement witheaCh pair of shoulder means.
 4. A sensor comprising, in combination, asupport, an elongated annular guide secured to the support, an annularoperator mounted within the guide for movement between actuated andunactuated positions and including a peripheral radially outwardlyopening groove, means biasing the operator to actuated position, aseismic mass, shaft means pivotally mounting the mass on the guide formovement independently thereof about a fixed axis transverse of thedirection of movement of the operator, a pair of grooves on the massopening toward the operator groove and directed axially and radially ofthe mass axis, each cooperating with the operator groove to providecooperating pairs of shoulder means, a ball engageable with eachcooperating pair of shoulder means to block pivotal movement of the massand hold the operator in unactuated position, said seismic mass beingresponsive to an acceleration pulse of predetermined amplitude and timedirected generally angularly to the mass axis to swing the mass aboutsuch axis and move the grooves thereof out of cooperating relationshipto the operator groove to permit the biasing means to move the operatorto actuated position as the balls move out of engagement with each pairof shoulder means, a plane bisecting the grooves containing the massaxis and the centers of the balls.
 5. A sensor comprising, incombination, a support, an elongated annular guide secured to thesupport, an operator mounted within the guide for movement betweenactuated and unactuated positions, means biasing the operator toactuated position, an annular seismic mass surrounding the guide, shaftmeans pivotally mounting the mass adjacent one end thereof on the guidefor independent movement relative thereto about a fixed axis transverseof the direction of movement of the operator, cooperating pairs ofshoulder means on the operator and mass adjacent the other end thereof,a ball engageable with each cooperating pair of shoulder means to blockpivotal movement of the mass and hold the operator in unactuatedposition, the centers of the balls being coplanar with the mass axis,said seismic mass being responsive to an acceleration pulse ofpredetermined amplitude and time directed generally normal to the massaxis and intermediate the ends thereof to swing the mass about such axisand move the shoulder means thereof out of cooperating relationship tothe operator shoulder means to permit the biasing means to move theoperator to actuated position as the balls move out of engagement witheach pair of shoulder means.